Near-Field Communication Tag for Colorimetric Glutathione Determination with a Paper-Based Microfluidic Device Ortiz Gómez, Inmaculada Rivadeneyra Torres, Almudena Salmerón, José F. Orbe Payá, Ignacio De Morales Santos, Diego Pedro Capitán Vallvey, Luis Fermín Salinas Castillo, Alfonso muPAD NFC tag Smartphone Colorimetric assay Glutathione determination Health prognosis Here, we propose a microfluidic paper-based analytical device (mu PAD) implemented with a near-field communication (NFC) tag as a portable, simple and fast colorimetric method for glutathione (GSH) determination. The proposed method was based on the fact that Ag+ could oxidize 3,3';,5,5'-tetramethylbenzidine (TMB) into oxidized blue TMB. Thus, the presence of GSH could cause the reduction of oxidized TMB, which resulted in a blue color fading. Based on this finding, we developed a method for the colorimetric determination of GSH using a smartphone. A mu PAD implemented with the NFC tag allowed the harvesting of energy from a smartphone to activate the LED that allows the capture of a photograph of the mu PAD by the smartphone. The integration between electronic interfaces into the hardware of digital image capture served as a means for quantitation. Importantly, this new method shows a low detection limit of 1.0 mu M. Therefore, the most important features of this non-enzymatic method are high sensitivity and a simple, fast, portable and low-cost determination of GSH in just 20 min using a colorimetric signal. 2023-03-27T08:14:10Z 2023-03-27T08:14:10Z 2023-02-13 journal article Ortiz-Gómez, I... [et al.]. Near-Field Communication Tag for Colorimetric Glutathione Determination with a Paper-Based Microfluidic Device. Biosensors 2023, 13, 267. [https://doi.org/10.3390/bios13020267] https://hdl.handle.net/10481/80860 10.3390/bios13020267 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional MDPI